Field of the Invention
The present invention relates to thermal management in an air cooled compute node chassis.
Background of the Related Art
Compute nodes include a number of electronic components that perform work and generate undesirable heat. Much of this heat must be removed from heat-generating electronic components, such as processors, in order to avoid high temperatures that can damage the components. Many of the heat-generating electronic components are coupled to a generally planar circuit board or motherboard or are disposed in some specific relation to the circuit board and the other components. The circuit board allows for the distribution of electrical current and the communication of data to and from the heat-generating electronic components. While the arrangement of components on the circuit board is somewhat flexible, certain components that work together or require fast, accurate data transfer should be positioned close together.
Heat generated by an electronic component may be transferred by conduction to a heat sink having a plurality of fins, pins or other high surface area structure for contact with air flowing through a computer chassis housing the circuit board. One or more air movers, such as fans, may be used to move air through the compute node chassis so that the air will flow across the fins to enhance dissipation of heat from the heat sink. Air movers are fixed relative to the computer chassis to draw air into one end of the chassis, across components disposed within the chassis, and then through the air movers to exit the chassis.
However, a compute node may experience changes in configuration and operation that affect the ability of air cooling to manage the temperature of the components. For example, removing a dual in-line memory module (DIMM) from a compute node forms an area of low airflow resistance such that cool air may channel past adjacent DIMMs without removing much heat. As another example, a processor or disk drive may handle a workload that varies over time, such that the amount of heat generated by the component varies similarly. Accordingly, a compute node may utilize additional strategies for managing the temperature of the components, such as throttling a processor to reduce its heat generation before it gets so hot as to damage itself. While effective, processor throttling represents a loss of performance. Even increasing the air flow rate through the chassis is not always the best way to prevent high temperatures, since fans consume increasing amounts of electricity at higher speeds.